Asset Dispositions and Impairments - Additional Information (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012
Impaired Long-Lived Assets Held and Used [Line Items]
Net cash proceeds from disposal of wholly-owned hotel	$ 61	$ 11
Three wholly-owned hotels [Member]
Impaired Long-Lived Assets Held and Used [Line Items]
Net cash proceeds from disposal of wholly-owned hotel	61
Number of wholly-owned hotels sold	3
Term of agreements	20
Pre-tax loss on sale of wholly-owned hotel	8
Wholly-owned hotel one [Member]
Impaired Long-Lived Assets Held and Used [Line Items]
Net cash proceeds from disposal of wholly-owned hotel		11
Number of wholly-owned hotels sold		1
Term of agreements		20
Pre-tax loss on sale of wholly-owned hotel		$ 7